This invention generally pertains to fastener assemblies. More specifically, the present invention relates to a washer member having a nut secured thereto adjacent a selectively frangible area thereof.
The invention is particularly applicable to nut and wash assemblies which are utilized in fastening automobile body panels together. For this type of application, it is required that the assemble be able to bear up under high torque values while retaining a sealing function and not adversely affecting the quality of the joint. However, it will be appreciated by those skilled in the art that the invention has broader application and may also be adapted to use in many other fastening environments where it is necessary to fasten any two members to each other.
Several free spinning nut and washer assemblies are known to the art. One conventional assembly includes a sheet metal nut in the form of a cup having a tranverse wall provided with an opening. The edge portions of the opening are formed into thread form to cooperate with a threaded fastener. This nut is combined with a washer having a tubular portion received within the cup, and the combined nut and washer is provided with a yieldable sealing material normally extending therebeyond for direct engagement with an article on which the nut is to be used. The sealing element is comprised of plastic material or rubber, and completely fills the cavity within the tubular portion of the washer and the nut except for an axially extending opening aligned with the threaded fastener receiving opening of the nut. Such a conventional nut and washer assembly is expensive to produce and necessitates use of a sealing element which is separate from the washer. Moreover, under a torque load on the nut, the sealing element is forced upwardly around the fastener, thus acting as a lubricant and reducing torque values.
Another conventional nut and washer assembly includes a dome-shaped sheet metal washer and a metal nut joined to the washer by a frangible bonding element. After the nut and washer assembly is threaded onto a fastener, the nut is broken away from the washer for allowing the nut to compensate for other than a perpendicular relationship between the surface on which the washer rests and the fastener. This washer does not, however, serve a sealing function.
It has been considered desirable to provide an inexpensive nut and washer assembly in which the nut could be secured to a portion of the washer but would rotate independent of the washer to which it is secured, after a predetermined torque load has been reached. It has also been considered desirable to have a nut and washer assembly which would eliminate the separate sealing element while still providing an effective seal.
The subject invention meets the foregoing needs and others to provide a new and improved nut and washer assembly that yields better and more advantageous overall operational results.